Embodiments of the present invention pertain to the formation of films on a substrate. These films, including but not limited to Si, SiGe, SiC and SiGeC, in both their doped and undoped forms, are used in the manufacture of advanced electronic components. Such films exhibit various properties, such as morphology and doping concentrations, which must be controlled to within certain tolerances. The advances exhibited in electronics over the past few decades are the direct result of the ability of semiconductor foundries to increase circuit pattern densities. As these pattern densities increase, the tolerances for the thin films required to make the circuits become increasingly strict. Therefore, careful control of the formation of thin films, and the resultant properties of such films, is essential for continued advances in electronics. These aforementioned films are typically made in an apparatus of the type shown and described in U.S. Pat. No. 6,083,323.
A substrate typically has a top face upon which a film can be formed and a bottom face. To grow the film, the substrate is placed into a reaction chamber. The top face of the substrate faces a top surface of the reaction chamber; similarly, the bottom face of the substrate faces a bottom surface of the reaction chamber. During the film formation process, the substrate is heated according to process parameters.
As noted above, it would be desirable to provide methods and apparatus for providing improved control of film characteristics, including but not limited to growth rate, morphology, faceting, doping distributions, etc. It is also desirable to provide methods and systems that provide a high level of process repeatability.